William simon



NITED STATES PATENT OFFICE- WILLIAM SIMON, OF BALTIMORE, MARYLAND, ASSIGNOR TO THE BALTIMORE CHROME WORKS, OF SAME PLACE.

MANUFACTURE OF BICHROMATE OF POTA SH.

SPECIFICATION forming part of Letters Patent No. 342,646, dated May 25, 1886.

Application filed December-2, 1885. Serial No.1R4A63. (No specimens.)

To all whom it may concern.-

Be it known that [,WILLIAM SIMON, a citizen of the United States, residing in the city of Baltimore and State of Maryland, have invented certain new and useful Improvements in the Manufacture of Bichromate of Potash, of which the following is a full and clear description.

My method for the manufacture of bichromate of potassium consists in the conversion of chromate of sodium into bichromate of potassium by the addition of chloride of potas-' sium and of either hydrochloric or sulphuric acid to a solution of said chromate of sodium, when decomposition takes place, bichromate of potassium being formed,which is separated by crystallization, while the sodium salts (chloride or sulphate of sodium) which are formed may be obtained by boiling down the mother-liquor.

The above process may be carried outin two different ways, as follows:

First way: Ohromate of sodium or a solu tion of this salt is converted into bichromare of sodium by the addition of a mineral acid in the well known way, and then to the solution of bichromate of sodium thus obtained, and also containing a soda salt of the acid employed,(whioh soda salt may or may not be separated by boiling" down to a sufficient strength,) is added chloride of potassiu m, when the decomposition takes place, which is represented by the following equation:

NZL-JCI207 ZKCI KeCl'eO': QNaCl Bicliro- Chloride Bicliro- Chlomate of oi'potas mate of ride sodium. sium. p o t a sof sosium. dium.

Second way: To chromate of sodium, or to a solution of this salt, are added hydrochloric acid and chloride of potassium, when bichromate of potassium separates in crystals and is collected, while chloride of sodium is obtained by boiling down the mother-liquorand removing this salt, and from which motherliquor again bichromate of potassium crystallizes on cooling. The decomposition taking place is shown by the following equation:

ot'sodium. ofpotasc lomate of of s o ter.

siuin. r i c p o t asdiuni.

acid. slum.

Witnesses:

FELIX R. SULLIVAN, JAMES C. G. UNDUOH, I. W. KREBS. 

